Lifting-jack.



PATENTED SEPT. 17, 1907.

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J. C. RIGG.

LIFTING JACK. APPLICATION FILED JUNIza. 1907.

UNITED STATES PATENT OFFIOE.

JAMES C. RIGG, OF IIOOKTOWN, KENTIICKY, ASSIGNOR OF ONE-IIALF TO I. H. COLLIER, OF

i HOOKTOWN, KENTUCKY.

LIFTING-JACI Specification of Letters Patent.

Patented Sept. 17, 1907.

Application filed June 3, 1907. Serial No. 377,097.

To all whom it may concern:

Be it known that I, JAMES C. RIGG, a citizen of the United States, residing at I-Iooktown, in the county of Nicholas and State of Kentucky, have invented certain new and useful Improvements in Lifting-Jacks, of which the following is a specification.

This invention relates to lifting jacks of that type having a lever and a notched lifting bar, engaged by a pawl carried by the lever, and has for its object to improve the construction of such jacks, particularly with respect to the manner of engaging or disengaging the pawl, and with respect to the means for adjusting the lifting bar according to the height of the wagon axle or other work to be hoisted.

The invention is illustrated in the accompanying drawings, in which p Figure l is a side elevation of the device. Fig. 2 is a similar view with the near side plate of the standard removed, with the parts in one position. Fig. 3 is a similar view with the parts in another position. Fig. 4 is a horizontal section.

The standard of the jack is provided with a base 6 and consists of two side plates 7, preferably made of pressed steel or the like, spaced apart by spacing pieces or blocks 8. These parts are bolted or otherwise fastened together securely, and the lifting bar and operating pawls are located in the space between the side plates.

The lifting bar is4 indicated at 9 and slides up and down at the rear edge against the rear spacing piece 8, and it is provided with a head l0 of suitable form. On the front edge the bar has a rack ll the teeth of which are hooked or inclined downwardly. The rack is sunken into the bar, between flanges l2 projecting at each side thereof, forming spaces I3 between said `flanges and the rack, as shown in Fig. 4. These spaces form guides for the pawl which engages the rack.

The operating lever is indicated at I4, fulcrumed on a bolt l5 at ,the top of the frame, between the side plates thereof, and this lever, which may conveniently be made of wood, has metal side plates IG which project at the lower end thereof, the pawl being swung or pivoted between said side plates by a bolt 17. The pawl consists oi a pair of side plates 18 bolted together and spaced apart a proper distance to fit at their iront edges in the grooves l3'in the lifting bar, and they have extending therebetween a stout pin I9 in proper position to engage in any one ofthe notches in the ratchet` The pawl has a rearwardly-extending weighted arm 20 which normally holds the same in engagement with the rack, but the pawl may be disengaged by lifting the weighted arm, to swing the pawl out or back. To accomplish the same result -in another way the ends of the plates 16 have projections 21 struck up inwardly therefrom, in proper position to engage behind the pawl plates I8 when the lever 14 is swung up toward the vertical. When this is done the projections strike against the rear edges of the pawl plates and swing the plates out or forward in such position that the pin 19 will not catch in the notches, and so the lifting bar may be raised or lowered at will.

To control the drop of the lifting bar, a spring detent 22 is pivoted at 23 between the side plates and the standard and is arranged to engage in the notches of the rack, being normally held in a position to do so by a spring 24. This detent stops against a cross pin 25 thereunder, and sustains the weight on the lifting bar when the lever is eased off. The detent projects through a slot in the A spacing piece 8 at one edge of the standard, and has a treadle piece 2G so that it may be operated by the foot Pressure on said treadle piece will lift the detent so that it will not catch in the rack. This allows a quick drop of the lifting bar when desired.

In order to give a quick action or adjustment to readily accommodate the jack to wagons or Work of different heights, a foot lever 27 is provided, fulcrumed at 28 near the base of the standard and projecting at its inner Y end under the foot of the lifting bar, its outer end being provided with a treadle so that it may be operated. When the lifting bar is down, it may be raised to any desired adjustment by pressing on the treadle of the lever 27 which will raise the bar until the head thereof strikes the work. The detent 22 and the pawl at the head of the lever allow the necessary slip.

In operation, the lifting bar being adjusted to the work in the manner stated, the bar is raised by manipulation of the lever in an obvious inanner.- The detent 22 holds the weight after each stroke of the lever and the pawl slips down over the teeth, and is swung into engagement by the weight, for the next stroke. To lower the load, the detent is disengaged by pressing down on its foot piece 26 after which the lever may then be eased off. For a quick drop, when not loaded, the detent is disengaged from the lifting bar, and the lever is swung up until the projections.2l strike the pawl and swing the same out of engagement with the bar, after which the bar will drop by its weight to the lowest position. The bar may be quickly raised to adjustment by foot pressure on the lever 27, which will run the bar up to the desired height without any operation or movement of the hand lever.

I claim:

1. The combination with a lifting bar having a ratchet and grooves in the bar beside the ratchet, of a lever, and a pawl carried thereby and arranged to engage the ratchet and having side plates the edges of which fit in the gr'ooves.

2. The combination of a standard, a ratchet lifting bar slidable up and down therein, a lifting lever fulcrulned on the standard and having a depending pawl hanging 10 therefrom and adapted to engage the ratchet, a rearwardly extending weighted arm en the pawl, and a projection on the lever bearing against the upper edge of the pawl and adapted to disengage the same from the ratchet when the lever is swung up to inoperative position.

In testimony whereof I atlx my signature, in presence 15 of two witnesses.

JAMES C. RIGG.

Witnesses: f

J. H. COLLIER, BENJAMIN F. GOLDNAUER. 

